On Sunday, January 26, 2020 at 5:24:46 PM UTC-7, John Clark wrote: > > On Sun, Jan 26, 2020 at 6:39 PM Alan Grayson <[email protected] > <javascript:>> wrote: > > *> I objected recently to Brent's claim that light from a galaxy in our >> non-observable region can cross our event horizon.* > > > It's just the opposite. >
You misunderstand. What I thought Brent posted, was that if a photon is in our non-observable region, it could cross our event horizon (and therefore become visible). If that's what he claimed, I think it's wrong. AG > Regardless of if space is positively curved or negatively curved or as > flat as a pancake, if the universe is accelerating and not just expanding > then galaxies in our OBSERVABLE region will eventually cross over our event > horizon into our UNOBSERVABLE region, > How many times must I say this? It does NOT depend on acceleration, just expansion, because the effect is purely geometrical, which I earlier explained. AG > and there is no way to tell how much is already there, no way to know if > that unobservable region is finite or infinite because it is...well... > unobservable. > There is a physical clock for the universe, namely, the temperature of the CMBR. Moreover, the curvature at any time t, is the same everywhere, if the universe is a hyper-sphere, So if you want to calculate its radius, all you need is its curvature! -- which, I conjecture, will one day be able to be measured. And that measurement need NOT include the unobservable region. AG > > John K Clark > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/39a551c2-93e6-4b24-a6bf-08c849843cb4%40googlegroups.com.
